Type bar action for typewriting machines



June 13, 1950 c. T. RICE 2,511,009

TYPE BAR ACTION FOR TYPEWRITING MACHINES Filed July 26, 1947 2 SheetsSheet 1 INVENTOR CLAUDE 7'. R765 ATTORNEY June 13, 1950 c. T. RICE 2,511,009

TYPE BAR ACTION FOR TYPEWRITING MACHINES Filed July 26, 1947 2 Sheets-Sheet 2 lNVENTOR CLfll/DE 7T RICE v ATTORNEY Patented June 1? 1950 UNITED STATES PATENT TYPE BAR ACTION FOR-TYPEWRITING' MACHINES 6 Claims.

This invention relates to writing machine or typewriter actions. in general, and more especially to silent or noiseless typewriter actions, this application constituting. a continuation in, part of my co-pending application, Ser. No. 686,620, filed July 27, 1946.

Among theobjects of the present invention it is aimed to-provide an improved silenttypewriter action including an actuating key, a type bar and a connecting mechanism which effects a variable motion includingan accelerated initial motion, a decelerated second motion after the type head of the type bar selected has been brought into printing position, and then a third motion resulting from. the momentum, generated by the initial motion simulating a. pressure blow as distinguished from a striking blow.

More specifically, the present invention aims to provide an. improved typewriter action using a toggle linkage to generate an initial accelerated motion, a second decelerated motion when the toggle linkage approaches dead center, and a third motion resulting from the momentum generated by'the. initial motion to enable said toggle linkage. to pass dead center and while doing so bring into. action a. decelerating medium.

These and other features, capabilities and advantages of the present invention will appear from the subjoined detail description of specific embodiments thereof illustrated in the accompanying drawings, in which Figs. 1 and 2' illustrate successive positionsin side elevation of one embodiment.

Figs. 3 and 4 illustrate successive positions in side elevation of a second embodiment.

In the embodiment illustrated in Figs. 1 and 2, the platen I is illustrative of the class of platens in which the platen is shifted to receive the upper case characters, being illustrated in its descended, normal position, to receive lower case characters. The type bar 2 is pivotally mounted on the. fixed pin or shaft 3, being provided with a head 4v having a lower case character 5 and an upper case character 6. The key bar I, il1ustrative of the conventional key bar, is pivotally mounted at one end on the fixed pin or shaft 8', and at its other end provided with a conventional key 9.

In the interest of an understanding of the operation of this embodiment and to show its relation to the other embodiment hereinafter to be described, it is here to be noted that in both embodiments there are only four fixed pivot pins, such as the pivot pins 3 and 8 aforesaid and the The pivot.- pin: Ill, extends: through. the angle or bend. inther bell crank. lever on bent lever l l, which haste: broadarm, l2 and a: long arm Hi. The arm 12 has connected thereto, the tension spring I4 formaintaining the; typewriter action at rest 'and in, turn for returning the typewriter action to normal position. or position of rest after actuation thereof; inaccordance with convention.

Thelong arm l3; forms a toggle linkage with the link. I5, the action of which constitutes an p -n if not e main, feature of the present ii-ivention.v The link. I5; is pivotal-1y connected at one endto. the free end: of the arm l3 and at its other end ispivotally connected to the short link I36x constituting; a part of the control for the type bar 2. The link It is fulcrumed or pivoted intermediate itsends to the; upper end: of the link I! constituting another part of' the control for the type bar 2, the lower'end of which link IT is pivotally connected to theshort arm or extension l8 integral with the type bar 2.

The link l5 functionally divided into two arms I9 and- 2B, the arm l9 cooperating with the arm- [-3 to form a toggle linkage, the movement of which from the dotted line position shown in Fig. 1; toward the full line position shown in Fig. 1, upon actuation effecting an accelerated, rapid initial, motion, the movement of which when approaching: and passing the dead center, the full line position shown in Fig. 1, being decelerated, and the motion of which from the full line position of Fig. l to the full line position in Fig. 2 simulating a pressure blow as distinguished from a striking blow to effect a silent or noiseless print: ing impression bythe type bar 2.

To aid in efiecting a uniform pressure blow by a plurality of actions, and in properly positioning the type bar 2' preparatory to an actuation, preferably there is provided a stop 2| which, in the present instance, is positioned to engage the rear face of the type. head 4 of the type bar 2, as shown the dotted line position of- Fig. 1.

Furthermore, to limit the arm H of the lever l I in the, final printing position of the type bar 2 and thereby prevent. any repeat. printing actio by the, type bar 2, preferably a second step 22 is provided. in the present, instance positioned to engage the upper edge of the, arm it. in the printins Position of the type bar 2.,

The key bar 1. i t present. nstance. cooper.- ates wi t ink l1 a d t ba 2. o eff ct a deceleration of the type bar 2 as it moves through its third motion, and also to eifect initial actuation of the type bar 2. The key bar 'l is piv-,

pivot pins H1 and 23 hereinafter to be described. otallyconnected intermediate its ends to one end of the link 24, the other end of which is pivotally connected to one arm 25 of the bell crank 26,- pivoted on the pivot pin 23, the other arm 21 03 which bell crank 26 is pivotally connected at its free end to one end of the link 28, the other end of which link 28 is connected to the free end of the short arm 18. In this embodiment it will be seen that the link I! is pivotally connected to the short arm or extension I8 intermediate its free; end and the pivot pin 3.

The embodiment illustrated in Figs. 3 and 4 is substantially identical to the embodiment illustrated in Figs. 1 and 2 except that the key bar 29 is pivotally connected intermediate its ends to one end of the link 30, the other end of which link 30 is connected to the arm 3i of the bell crank lever 32 which is pivoted on the fixed pivot pin 33. The free end of the other arm 34 of the bell crank lever 32 is pivotally connected to one end of the link 35, the other end of which link 35 is pivotally connected to the free end of the arm 36 of the link 31 which takes the place of the link I! illustrated in the embodiment of Fig. 1. The link 3! is pivotally connected intermediate its long arm 38 and its short arm 36 to the free end of the short arm or extension 39 of the type bar 40. The embodiment illustrated in Figs. 3 and 4, therefore, differs from the embodiment illus trated in Figs. 1 and 2, primarily in that the key bar 29 through the linkage 3U, 32 and 35 is connected to the free end of the link 31, whereas the key bar 1 of the embodiment illustrated in Fig. l is connected by the linkage 24, 26 and 28 to the free end of the extension or short arm l8 of the type bar 2 and not directly connected to the link H.

In both embodiments, however, it will appear that there is a restraining action exercised on the toggle linkage formation by the key bar'and its associated linkage when the toggle linkage formation executes its third motion, that is, to and beyond dead center.

In the embodiment illustrated in Figs. 3 and 4, the key bar 29 cooperating with the linkage 30, 32 and 35 positively opposes the movement of the arm 4| and link 42 from the full line position shown in Fig. 4 into the dash and dot line position shown in Fig. 4, thereby to restrain the action when executing its third motion or printing action.

This restraining action is eifected, as aforesaid, either by directly or indirectly connecting the extension or short arm of the type bar with the key bar. In the embodiment illustrated in Figs. 1 and 2, the key bar 1 is connected by the linkage 24, 2t and 28 to the short arm or extension [8 while in the embodiment illustrated in Figs. 3 and 4, the key bar 29 is connected by the linkage 33, 32, 35 and 36 to the short arm or extension 39 of the type bar 40.

From the foregoing it will appear that in the embodiment illustrated in Figs. 1 and 2, the arm l3, links I5, [6 and I! and type bar 2 may conveniently be grouped as one linkage for controlling the type head 4, while moving into printing position, and that the key bar 1, linkage 24, 26 and 28 and short arm 45 of the extension l8 may be grouped as the second linkage for initiating the actuation of the mechanism. Similarly in the embodiment illustrated in Figs. 3 and 4, the arm 4|, links 42, 43, arm 38 and type bar 40 may conveniently be grouped as one linkage for controlling the type head 44, and the key bar 29, linkage 30, 32 and 35 and arm 36 of the link 3'! may be conveniently grouped as the second linkage for initiating the actuation of the mechanism.

It is obvious that various changes and modifications may be made to the details of construction without departing from the general spirit of the invention as set forth in the appended claims.

I claim:

1. The combination with a platen, of a key bar pivotally mounted on a fixed pivot, a first linkage including a type bar having a head at one end and pivotally mounted on a fixed pivot, a lever fulcrumed on a fixed pivot, a spring connected to one arm of said lever for normally maintaining said linkage in position of rest and for restorin it to position of rest, a first link pivotally connected at one end to the free end of the other arm of said lever, a control including a first means and a second means, said first means extending from said type bar adjacent its pivot to said first link and pivotally connected to said first link intermediate its ends, said second means operatively associating the other end of said first link with said type bar adjacent its head to vary the distance between said head and said other end of said link as the head is moved into and out of printing relation to said platen, and a second linkage operatively connected at one end to said key bar and at its other end to said type bar to actuate said first linkage and therewith said type bar into printing relation with said platen when said key bar is actuated in opposition to said spring, said lever and first link forming a toggle action and when actuated by said key bar executing an initial accelerated motion before reaching dead center and thereupon executing a decelerated motion when passing dead center.

2. The combination with a platen, of a key bar pivotally mounted on a fixed pivot, a first linkage including a type bar having a head at one end and pivotally mounted on a fixed pivot, said type bar having an extension beyond its fixed pivot, a lever fulcrumed on a fixed pivot, a spring connected to one arm of said lever for normally maintaining said linkage in position of rest and for restoring it to position of rest, a first link pivotally connected at one end to the end of the other arm of said lever, a control including a first means and a second means, said first means extending from said extension to said first link and pivotally connected to said first link intermediate its ends, said second means operatively associating the other end of said first link with said type bar adjacent its head to vary the distance between said head and said other end of said link as the head is moved into and out of ,printing relation to said platen, and a second linkage operatively connected at one end to said key bar and at its other end to said extension to actuate said first linkage and therewith said type bar into printing relation with said platen when said key bar is actuated in opposition to said spring, said lever and first link forming a toggle action and when actuated by said key bar performing an initial accelerated motion before reaching dead center and thereupon performing a decelerated motion when passing dead center.

3. The combination with a, platen, of a key bar pivotally mounted on a first fixed pivot, a first linkage including a type bar having a head at one end and pivotally mounted on a second fixed pivot, said type bar having an extension beyond its fixed pivot, a lever fulcrumed on a third fixed pivot, a spring connected to one arm of said lever for normally maintaining said first linkage in position of rest and for restoring it to position of rest, a first link pivotally connected at one end to the free end of the other arm of said lever, a control including a first means and a second means, said first means extending from said extension to said first link and pivotally connected to said first link intermediate its ends, said second means operatively associating the other end of said first link with said type bar adjacent its head to vary the distance between said head and said other end of said link as the head is moved into and out of printing relation to said platen, and a second linkage operatively connected at one end to said key bar and at its other end to said first means to actuate said first linkage and therewith said type bar into printing relation with said platen when said key bar is actuated in opposition to said spring, said lever and first link forming a toggle action and when actuated by said key bar executing an initial accelerated motion before reaching dead center and thereupon executing a decelerated motion when passing dead center.

4. The combination with a platen, of a key bar pivotally mounted on a first fixed pivot, a first linkage including a type bar having a head at one end and pivotally mounted on a second fixed pivot, said type bar having an extension beyond its fixed pivot, a first lever fulcrumed on a third fixed pivot, a spring connected to one arm of said lever for normally maintaining said first linkage in position of rest and for restoring it to position of rest, a first link pivotally connected at one end to the free end of the other arm of said lever, a control including a second lever and a second link, one arm of said second lever extending from said extension to said first link and pivotally connected to said first link intermediate its ends, said second link operatively associating the other end of said first link with said type bar adjacent its head, and a second linkage operatively connected at one end to said key bar and at its other end to the other arm of said second lever to actuate said first linkage and therewith said type bar into printing relation with said platen when said key bar is actuated in opposition to said spring, said first lever and first link forming a toggle action and when actuated by said key bar executing an initial accelerated motion before reaching dead center and thereupon executing a decelerated motion when passing dead center.

5. The combination with a platen, of a key bar pivotally mounted on a fixed pivot, a first linkage including a type bar having a head at one end and pivotally mounted on a fixed pivot, said type bar having an extension beyond its fixed pivot, a lever fulcrumed on a fixed pivot, a spring connected to one arm of said lever for normally maintaining said linkage in position of rest and for restoring it to position of rest, a first link pivotally connected at one end to the end of the other arm of said lever, a control including a first means and a second means, said first means extending from said extension to said first link and pivotally connected to said first link intermediate its ends, said second means operatively associating the other end of said first link with said type bar adjacent its head, a second linkage operatively connected at one end to said key bar and at its other end to said extension to actuate said first linkage and therewith said type bar into printing relation with said platen when said key bar is actuated in opposition to said spring, said lever and first link forming a toggle action and when actuated by said key bar performing an initial accelerated motion before reaching dead center and thereupon performing a decelerated motion when passing dead center, said second linkage including a bell crank mounted on a fixed pivot, a second link operatively connecting one arm of said bell crank with said key bar, and a third link operatively connecting the other arm of said bell crank with said extension.

6. The combination with a platen, of a key bar pivotally mounted on a first fixed pivot, a first linkage including a type bar having a head at one end and pivotally mounted on a second fixed pivot, said type bar having an extension beyond its fixed pivot, a first lever fulcrumed on a third fixed pivot, a spring connected to one arm of said lever for normally maintaining said first linkage in position of rest and for restoring it to position of rest, a first link pivotally connected at one end to the free end of the other arm of said lever, a control including a second lever and a second link, one arm of said second lever extending from said extension to said first link and pivotally connected to said first link intermediate its ends, said second link operatively associating the other end of said first link with said type bar adjacent its head, a second linkage operatively connected at one end to said key bar and at its other end to the other arm of said second lever to actuate said first linkage and therewith said type bar into printing relation with said platen when said key bar is actuated in opposition to said spring, said first lever and first link forming a toggle action and when actuated by said key bar executing an initial accelerated motion before reaching dead center and thereupon executing a decelerated motion when passing dead center, said second linkage including a bell crank pivotally mounted on a fourth fixed pivot, a third link operatively connecting one arm of said bell crank with said key bar, and a fourth link operatively connecting the other arm of said bell crank with the other arm of said second lever.

CLAUDE T. RICE REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,767,876 Going June 24, 1930 1,951,453 Stickney Mar. 20, 1934 

